This program consists of studies which integrate the disciplines of surgery, hematology, chemistry, pathology, engineering and physiology and the skills and resources of the fabrication industry in a major effort to develop an arterial prosthesis which can serve as a back-up for the saphenous vein as an aortocoronary bypass. Background work in this Center suggests that specially designed and constructed porous fabric prostheses for aortocoronary bypass can be kept open by platelet inhibition until their flow surface has become endothelialized. Such grafts will then be able to maintain long-term patency without further anti-thrombotic therapy.